1. Field of the Invention
The invention relates to an imaging apparatus and an image processing method that process a pixel output of an imaging element that detects a focusing state using part of pixels as focus detection elements of a phase difference method.
2. Description of the Related Art
For example, Japanese Patent No. 3592147 presents an imaging apparatus that detects a focusing state using part of pixels of an imaging element as focus detection elements. The imaging apparatus of Japanese Patent No. 3592147 sets part of pixels of an imaging element as focus detection pixels, images subject luminous fluxes that have passed through different pupil regions that are symmetrical with respect to the center of the optical axis of the imaging lens on a plurality of focus detection pixels, and detects a phase difference between the subject luminous fluxes, to detect the focus state of the imaging lens.
For example, part of the region of each focus detection pixel is shielded from light to receive one of the subject luminous fluxes that have passed through the different pupil regions of the imaging lens. For this reason, each focus detection pixel serves as a defective pixel that is not usable as a pixel as it is. For this reason, an imaging apparatus disclosed in Jpn. Pat. Appln. KOKAI Pub. No. 2010-062640 has a structure of performing gain control on the pixel output of each focus detection pixel or interpolating the pixel output using peripheral pixels to enable use of the focus detection pixel for recording and display.